Quantum speed limit of a single atom in a squeezed optical cavity mode

Abstract

We theoretically study the quantum speed limit of a single atom trapped in a Fabry–Perot microresonator. The cavity mode will be squeezed when a driving laser is applied to the second-order nonlinear medium, and the effective Hamiltonian can be obtained under the Bogoliubov squeezing transformation. The analytical expression of the evolved atom state can be obtained by using the non-Hermitian Schrödinger equation for the initial excited state, and the quantum speed limit time coincides very well for both the analytical expression and the master equation method. From the perspective of quantum speed limit, it is more conducive to accelerate the evolution of the quantum state for the large detuning, strong driving, and coupling strength. For the case of the initial superposition state, the form of the initial state has more influence on the evolution speed. The quantum speed limit time is not only dependent on the system parameters but also determined by the initial state.